Executive brief
BuildKit is a toolkit used for converting source code into build artifacts like Docker images. A security flaw exists where specialized build tools or custom frontends using BuildKit's low-level interface can be tricked into executing unauthorized commands on the host system. This occurs when a build process interacts with a malicious Git repository, potentially allowing an attacker to gain control over the build environment.
Technical details
A command injection vulnerability (CWE-88) exists in BuildKit when using the raw low-level API to check out Git sources. If a client or custom frontend sets the 'git.checkoutbundle=true' option, BuildKit may improperly neutralize argument delimiters when handling the Git source. An attacker providing a malicious Git repository can exploit this to achieve arbitrary command execution on the host running the BuildKit daemon. This vulnerability specifically affects versions v0.30.0 through v0.31.1 and requires the use of a custom frontend; standard Dockerfile builds are reportedly not affected. The issue is patched in version v0.31.2.
Affected products
- Moby BuildKit v0.30.0 - v0.31.1
Timeline
- 2026-07-16: advisory: GitHub advisory published by maintainers
- 2026-07-21: disclosed: NVD publication date
- 2026-07-21: patched: Fix released in version 0.31.2